It has become well established that there are major public health benefits from regular endoscopic examinations of patients' internal structures such as the alimentary and excretory canals. In any endoscopic procedure, there is always a need for the introduction and evacuation of different types of fluids, such as water, saline, drugs, contrast material, dyes, or emulsifiers. One such endoscopic procedure is a colonoscopy, which is an internal examination of the colon by means of an instrument called a colonoscope. A standard colonoscope is typically 135-185 cm in length and 12-13 mm in diameter and includes a fiber optic imaging bundle, illumination fibers, and an instrument or working channel that may be used for the delivery of tools into the patient and the vacuum evacuation of liquids. The colonoscope is inserted into the colon via the patient's anus and is advanced through the colon, allowing direct visual examination of the colon wall, the ileocecal valve, and portions of the terminal ileum. Approximately six million colonoscopies are performed each year.
In colonoscopic procedures, clear visualization of the entire colon, cecum and rectum is required for the procedure to be effective and efficient. It is estimated that about 20% of all colon polyps in patients are undetected due to low visibility, which can arise from poor colon preparation. Presently, about 10% of all colonoscopy patients are non-compliant with prescribed preparatory procedures and approximately 4% of all patients are unable to complete the exam due to an excess of stool in the colon. The remaining 6% are considered marginal, and the colonoscopy may still be performed if the colon is further evacuated as a part of the procedure. Conventionally, the marginal colons are cleared by repeatedly administering several small (e.g. 60 cc) fluid flushes through an endoscope's working channel by means of an ancillary apparatus that employs a low-volume wash and suction. The waste slurry is then removed with suction through the working channel in the endoscope. This tedious and inefficient process is limited by the amount of stool that can be removed with each flush. The process also causes a loss of productivity due to the added time required to fully evacuate the colon.
Conventional endoscopes are expensive hand-assembled medical devices costing in the range of approximately $25,000 for an endoscope, and much more for the associated operator console. Because of the expense, these endoscopes are built to withstand repeated disinfections and use upon many patients. Conventional endoscopes are generally built of strong composite materials, which decrease the flexibility of the endoscope and thus can compromise patient comfort. Furthermore, conventional endoscopes are complex and fragile instruments that frequently need expensive repair as a result of damage during use or during a disinfection procedure. A problem encountered with conventional endoscopes is the difficulty of sterilization between procedures. Sterilization of endoscopes may be accomplished with an autoclave, however, this tends to be harmful to the polymer components of the probe. Chemical bath sterilization may be used, however, this method cannot ensure complete removal of biological material that may become trapped within the channels of the endoscope probe.
Low cost, disposable medical devices designated for a single use have become popular for instruments that are difficult to sterilize or clean properly. Single use, disposable devices are packaged in sterile wrappers to avoid the risk of pathogenic cross-contamination of diseases such as HIV, hepatitis and other pathogens. Hospitals generally welcome the convenience of single use disposable products because they no longer have to be concerned with product age, overuse, breakage, malfunction and sterilization. One medical device that has not previously been inexpensive enough to be considered truly disposable is the endoscope, such as a colonoscope, ureteroscope, gastroscope, bronchoscope, duodenoscope, etc. Such a single-use or disposable endoscope is described in U.S. patent application Ser. No. 10/406,149 filed Apr. 1, 2003, Ser. No. 10/811,781, filed Mar. 29, 2004, and Ser. No. 10/956,007, filed Sep. 30, 2004, all assigned to Scimed Life Systems, Inc./Boston Scientific Scimed, Inc., which are incorporated herein by reference.
To overcome these and other problems, there is a need for a way to perform an irrigation and evacuation process prior to and/or during an endoscopy procedure upon poorly prepared or non-prepared patients, by use of an endoscope that is capable of preparing the patient and optionally also examining the patient. The endoscope can be reusable, or designed as a low cost endoscope that can be used for a single procedure and thrown away. The preparation and examination endoscope should be simple and easy to use in order to efficiently prepare patients for a colonoscopy procedure.